Lives themselves on Earth this is the Incredibles has excess capacity. They live quietly and don't touch anyone until show itself some vicious body and does not want to annoy a peaceful Earth. That's when they come into the case so that only the Pooh scatter such villains.
But for how long, and on the Earth all is quiet and peaceful. The Incredibles is resting peacefully and acquires a little fat until one very cunning villain prepares his evil plan. Whether this time save Super Heroes of humanity?